Influence of environmental manipulation on exploratory behaviour in male BDNF knockout mice.
It is widely accepted that brain derived neurotrophic factor (BDNF) plays a crucial role in mediating changes in learning and memory performance induced by environmental conditions. In order to ascertain whether BDNF modulates environmentally induced changes in exploratory behaviour, we examined mice carrying a deletion in one copy of the BDNF gene. Young heterozygous male BDNF knockout mice (BDNF+/-) and their wild-type (WT) controls were exposed to the enriched environment condition (EC) or the standard condition (SC) for 8 weeks. Exploratory behaviour was assessed in the open-field (OF) and hole-board (HB) test. Brains from EC and SC reared animals were processed for Golgi-Cox staining and the dendritic spine density in the dentate gyrus (DG) and CA1 hippocampal regions were examined. We found behavioural differences both due to the genetic modification and the environmental manipulation, with the BDNF+/- mice being more active in the OF whereas the EC mice had increased exploratory behaviour in the HB test. Environmental enrichment also led to an increase in dendritic spines in the hippocampal CA1 region and DG of the wild-type mice. This effect was also found in the enriched BDNF+/- mice, but was less pronounced. Our findings support the critical role of BDNF in behavioural and neural plasticity associated with environmental enrichment and suggest that besides maze learning performance, BDNF dependent mechanisms are also involved in other aspects of behaviour. Here we provide additional evidence that exploratory activity is influenced by BDNF.
Zhu
Shun-Wei
SW
Alzheimer's Disease Research Center, NVS Department, Karolinska Institutet, Stockholm 141 86, Sweden. shunwei.zhu@ki.se
Codita
Alina
A
Bogdanovic
Nenad
N
Hjerling-Leffler
Jens
J
Ernfors
Patrik
P
Winblad
Bengt
B
Dickins
David W
DW
Mohammed
Abdul H
AH
D000704:Analysis of Variance; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000502:physiology*; D049229:Dendritic Spines / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology / Q000502:physiology; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology*; D006579:Heterozygote; D006624:Hippocampus / Q000166:cytology / Q000502:physiology; D006799:Housing, Animal; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology
D019208:Brain-Derived Neurotrophic Factor